Multi-wall bulk bags are very commonly used for bulk storage and shipment of a wide variety of materials such as dry food products, powdered milk and whey and the like. And there are many different sizes and styles of such bulk bags, which are sometimes called flexible intermediate bulk containers. For example, multi-wall bulk bags are available with two or more layers, and many such bags include a plastic liner as the innermost layer. One typical type of a bulk multi-wall bag has an outer layer of heavy paper such as kraft paper, a middle ply of paper, an inner ply of paper and a plastic liner that is often laminated to the inner paper layer. One end of the bag is closed, and “block bottom” and “pinch” closures are fairly standard and conventional. The opposite end of the bag remains open when the bag is originally manufactured. The open end is closed and sealed by the end user after the bag has been filed.
In use, the empty bag is filled by the customer with the bulk material and, once filled, the open end is closed to make the bag ready for shipment and storage. There are many different ways that the open end of a filled bag may be closed. Regardless of what type of closure is used, a common and important aspect of the closure is that the closure must define a complete seal so that the integrity and product life of the contents of the bag is enhanced. Both pinch-top and stitched-top bags are very conventional. A pinch-top closure is a type of closure where the layers of the bag are pinched together and heated to seal the open end. A stitched-top bag typically has a tape folded over the upper edges of the bag and stitching extending laterally across the tape. There are several different stitching styles used, and chain and over lock stitching patterns are common examples. There are additional types of closure systems for the open end of bulk bags. For instance, the bag described herein and according to the present invention utilizes a closure defined by a stepped flap that extends from the back panel of the bag, and which is folded over the front panel of the bag and then sealed to the front panel to complete the closure.
Regardless of the type of closure that is used, the end user must open the closed top end of the bag to access its contents. How the bag is opened typically depends on the type of closure. For example, with a pinch-top closure the end user often uses a sharp knife to open the bag—a slit is made laterally across the bag near the upper edge and through the layers of the bag. With a stitched-top bag, it is often possible to pull the stitching out by pulling a specific thread used in the stitch pattern. Some bags incorporate “easy-open” features that allow the user to open the bag without a knife, and without pulling stitching. Often, these easy-open features are incorporated into cover sheets called patches that are glued onto and cover the folded bottom ends of the outer paper layer during manufacture. The user tears off the patches to allow access to the contents of the bag.
Despite the availability of many different sizes and styles of bulk material bags, including such bags with easy open features, there is a need in the industry for bags that facilitate reliable and fast opening by the end user. Using knives to open bags brings inherent dangers of the user being injured. Tearing out chain lock stitching can be problematic and does not always allow for quick opening.
The present invention is an easy open apparatus and system for bulk material bags that overcomes the problems typically associated with existing bags. The invention is illustrated in FIGS. 1 through 6, which may also be taken as a sequence of drawings that illustrate the steps utilized to assemble the easy open apparatus according to the invention.
The invention comprises an easy open apparatus and system for multi-wall bags and a method for making such bags. The invention is illustrated and described herein in respect of a 3 play block bottom bag. However, it will be readily appreciated that the easy opening feature may be incorporated into a variety of different types of bulk bags.